Lockheed Martin is the largest defense contractor in the world, and the F-35 fighter program alone accounts for a substantial share of its revenue, a franchise expected to fly for decades. Missiles and fire control, helicopters through Sikorsky, and space systems round out the portfolio. Nearly all sales go to the US government and allied nations, making the order book a function of geopolitics and defense budgets rather than economic cycles. The company took its modern form in the 1995 merger of Lockheed and Martin Marietta.